The deployment of IPTV systems and triple play applications boosts the interactive services in the digital home. One of the key benefits for interactive television viewers is to provide them with broadcast programs with real-time voting. For example, in an interactive program, such as a reality show, a song or dance contest, viewers are encouraged to send feedback or responses to the program by the following means: e-mail, web voting, short message service via mobile terminals, telephone voting; thus the interest and support rate for candidate actors/competitors can be calculated. Furthermore, in some other types of interactive programs such as quiz events, talk shows, even some news programs, the viewers are also afforded the possibility of entering their answers and selections representative of their comments. Normally, there exist two methods to implement interactive voting.
The first one is to provide supplementary information associated with interaction operations, e.g. by displaying a web site address or a telephone number. The participant viewers use additional devices such as telephones, mobile telephones or PCs to send feedback. The shortcomings of this method lie in the following aspects:
a) Additional network resources and a voting platform are required to work with the television program; and
b) The voting behavior of viewers is spontaneous and generally unpredictable. There is no traffic control and congestion control for a mass of feedback sent by viewers in a short period of time; and
The second one is to transmit feedback through a set-top-box connecting to the television, as long as a return channel is available in the IPTV system. The supplementary information can be displayed by the television as an alternative to the program schedule, or it can be superimposed on the current program, or else it can be represented on a second screen such as a tablet or a notebook that has an IP connection with the receiver (e.g. a Set Top Box or ‘STB’). Although the second method can solve problems a) listed above. The problem b) is hard to solve because in the described voting mechanism, the voting requests are broadcasted with the TV program and there is no traffic control at the terminal side. For those popular programs with a large number of viewers, such as the Spring Festival Gala by China Central Television, which usually catches the attention of millions of viewers and assuming 10% of viewers are willing to make real-time voting for a song or dance program in a 5-minute interval, the amount of response messages is remarkable and can possibly generate congestion and service interruption in an interactive server.